Changed JSON fields on mutable objects in ActionLog object

Now is able partial update of additional_info (dict) field.

Change-Id: I7ab2bdbd9c155d4d9926da9a011786a8c207d770
Partial-Bug: 1482658

nailgun/nailgun/db/sqlalchemy/models/action_logs.py

@@ -16,6 +16,7 @@ from sqlalchemy import Boolean
 from sqlalchemy import Column
 from sqlalchemy import DateTime
 from sqlalchemy import Enum
+from sqlalchemy.ext.mutable import MutableDict
 from sqlalchemy import Integer
 from sqlalchemy import String
 
@@ -39,6 +40,10 @@ class ActionLog(Base):
     start_timestamp = Column(DateTime, nullable=False)
     end_timestamp = Column(DateTime, nullable=True)
     is_sent = Column(Boolean, default=False)
-    additional_info = Column(JSON, nullable=False)
+    additional_info = Column(
+        MutableDict.as_mutable(JSON),
+        default={},
+        nullable=False
+    )
     cluster_id = Column(Integer, nullable=True)
     task_uuid = Column(String(36), nullable=True)

nailgun/nailgun/objects/action_log.py

@@ -45,12 +45,7 @@ class ActionLog(NailgunObject):
 
         :return: returned by parent class method value
         """
-
-        if data.get('additional_info'):
-            add_info = dict(instance.additional_info)
-            add_info.update(data['additional_info'])
-            data['additional_info'] = add_info
-
+        instance.additional_info.update(data.pop('additional_info', {}))
         return super(ActionLog, cls).update(instance, data)
 
     @classmethod

nailgun/nailgun/test/unit/test_objects.py

@@ -901,12 +901,9 @@ class TestActionLogObject(BaseIntegrationTest):
             'is_sent': False,
             'cluster_id': 1
         }
-
-        al = self._create_log_entry(object_data)
-
-        instance_to_validate = jsonutils.loads(objects.ActionLog.to_json(al))
         self.assertRaises(jsonschema.ValidationError, jsonschema.validate,
-                          instance_to_validate, action_log.schema)
+                          object_data, action_log.schema)
+        self.assertRaises(ValueError, self._create_log_entry, object_data)
 
     def test_get_by_uuid_method(self):
         object_data = {